Process for removing metals from petroleum residua

ABSTRACT

A process is provided for removing metal contaminants such as vanadium, nickel and iron, particularly vanadium and nickel, from hydrocarbon fractions. The process comprises contacting the hydrocarbon with an extractant comprising molten sulfur and a Group VB metal salt.

United States Patent [1 91 Long [ Nov. 19, 1974 PROCESS FOR REMOVINGMETALS FROM PETROLEUM RESIDUA [75] Inventor: Robert Byron Long, AtlanticHighlands, NJ.

[7 3] Assignee: Exxon Research and Engineering Company, Linden, NJ.

22 Filed: June 8,1972

21 Appl. No.: 260,757 I [52] US. Cl. 208/251 R, 208/253 [51] Int. ClCl0g 17/00 [58] Field of Search 208/253, 251 I [56] References CitedUNITED STATES PATENTS 9/1958 Weller et al, 208/251 H 3,180,820 4/1965Gleim et al. 208/251 H 3,622,495 l/1970 Gatsis 208/251 H 3,622,49811/1970 Stolfa 208/251 H Primary Examiner-Delbert E. Gantz AssistantExaminer-Juanita M. Nelson Attorney, Agent, or Firm-Jay Simon [5 7ABSTRACT 20 Claims, No Drawings PROCESS FOR REMOVING METALS FROMPETROLEUM RESIDUA The present invention relates to the removal of metalcontaminants from hydrocarbon fractions. More particularly, the presentinvention relates to a process for removing heavy metals such asvanadium, nickel or iron, particularly vanadium and nickel, frompetroleum fractions such as crude oil or residual fractions.

Many hydrocarbon feedstocks contain appreciable amounts of heavy metalssuch as vanadium, nickel and iron or compounds thereof. These metalliccontaminants may exist within the hydrocarbonaceous material in avariety of forms, generally being present as complexed organometalliccompounds of relatively high molecular weight, for example as metalporphyrins and various derivatives thereof. These heavy metals or metalcompounds can deteriorate the activity of and poison certain types ofcatalysts, when present in feedstocks subjected to catalytic treatment.Cracking catalysts, such as silica-alumina catalysts, alone or inadmixture with other metal oxides suitable for cracking, areparticularly susceptible to deterioration and poisoning by heavy metalssuch as vanadium, iron and nickel and the like.

The problems surrounding the presence of these heavy metal contaminantshave long troubled those working in the art; however, efforts heretoforemade to reduce the levels of such contaminants have not been entirelysatisfactory. U.S. Pat. No. 2,854,399 states that petroleum fractionsderived from crude oils, and containing heavy metal componentsdeleterious to the cracking of such oils, can be catalytically crackedafter contacting such fractions with sulfur and removing any resultingheavy metal sulfides and excess elemental sulfur. While this method doesaid in reducing the levels of heavy metal contaminants, certain of thecontamimants, especially vanadium, remain in sufficient amounts torapidly poison the cracking catalysts. U.S. Pat. No. 3,474,029 relatesto a process for hydrorefining a metal contaminated,asphaltene-containing hydrocarbon charge stock. According to thispatent, the

. charge stock is contacted with a catalyst and hydrogen I in thepresence of a thioester of a metal selected from the group consisting ofmetals of Group VB and Group VlB to maintain the activity of thecatalyst. U.S. Pat.

9 No. 3,619,410 states that metallic contaminants can be removed duringthe conversion of hydrocarbonaceous black oils with hydrogen andhydrogen sulfide by the addition of an aqueous solution of the doublesalt vanadyl sulfite-ammonium sulfite. The approaches suggested by thelatter two patents require the use of costly materials and arerestricted to highly inflexible processing schemes.

It is an object of the present invention to provide a highly flexibleand efficient method for removing metal contaminants such as vanadium,nickel and iron from hydrocarbon fractions.

This and other objects are accomplished by the presentinvention whichprovides a process for reducing the level of metal contaminants in ahydrocarbon material which comprises contacting the hydrocarbon with anextractant comprising elemental sulfur and a Group VB metal salt, andthereafter separating at least a portion of the extractant and metalcontaminants from said hydrocarbon material.

While any hydrocarbon feedstock containing metal contaminants can betreated according to the process of the present invention, this processis particularly suitable for removing metal contaminants from petroleummaterials such as crude oil or residual fractions,

' especially from long residua (a major portion of the fraction boils inexcess of 460F at atmospheric pressure) and short residua (a majorportion of the fraction boils in excess of l,000F at atmosphericpressure). The hydrocarbon materials may typicially contain from about100 to 3,000 wppm vanadium, 10 to 1,500 wppm ides, and selenides ofvanadium, niobium and tantalum.

Vanadium sulfides, especially vanadium sesquesulfide (V 8 and vanadiumpentasulfide (V 8 or mixtures thereof, are particularly preferred. TheGroup VB metal salt can be-either supported or unsupported. Whenunsupported it can be added before or after admixture of the hydrocarbonwith the sulfur. When supported, the Group VB metal salt is typicallydispersed on a support material such as silica, alumina, silicaalumina,titania, zirconia, thoria, and the like, and the hydrocarbon and moltensulfur are mixed and passed thereover. Whether the Group VB metal saltis supported or unsupported, the sulfur is used in an amount of fromabout 0.001 to 10 wt. percent based on the weight of the hydrocarbon,preferably 0.5 to 5.0 wt. percent, and most preferably 0.9 to 1.5 wt.percent. The Group VB metal salt functions as a promoter, and, whethersupported or unsupported, it must be used in an effective promotingamount. When unsupported, the Group VB metal salt is preferably presentin amounts ranging from 0.l to 10 wt. percent, most preferably 0.5 to2.0 wt. percent, based on the weight of the hydrocarbon feed. Whensupported, the hydrocarbon/- sulfur mixture is passed over the supportedGroup VB metal salt at a space velocity within the range of from about0.01 to 100, preferably 1 to 5, volumes of oil and sulfur per volume ofsupported Group VB metal salt per hour (v/v/hr.).

The treatment temperature employed according to the present inventionmust be sufficiently high in order to provide liquid phase contact;however, the treatment temperature should be below about 400C. Abovethis temperature substantial reaction of the sulfur with the hydrocarbonis experienced and undesirable sulfur compounds are produced. Typically,the treatment temperature ranges from about to 350C, and preferably fromabout 200 to 300C. The reaction zone pressure is not critical. Thecontacting period may range from about 0.1 to 10 hours, preferably fromabout 0.2 to 2 hours.

The sulfur/Group VB metal salt extractant and the hydrocarbon feed arepreferably contacted in amixing zone provided with a mixing apparatuscapable of causing intimate contact between the phases. Centrifugalpumps, mixing orifices. paddle wheels, and other high shear devices, orcombinations thereof, are suitable means for assuring intimate contactbetween the sulfur/Group VB metal salt extractant and the hydrocarbonbeing treated.

Following Contact of the hydrocarbon with the sul- The followingexamples are presented for the purpose of more clearly illustrating thepresent invention and are not to be taken as limiting the invention tothe particular reactants or conditions employed.

fur/Group VB metal salt extractant, the extractant con- 5 taining themetal contaminants (i.e., contaminant metals that are complexed and/orcompounded with the EXAMPLES l9 ig the Group Salts g q g unreactefl Ineach of the following examples, the designated Ur) g removed E i mater"amount of 460F+ residual cut from Venezuelan crude 5 may 6 remove Jmmelate y Y t e contact' 10 was contacted with the specified extractant ina pyrex mg step or after Subsequent Processing steps where tube that waspositioned within an oil bath maintained P sqbsequem steps not resultadversfi reac' at the indicated temperature. This residua containedtlons with, or be retarded by, the presence of these ma- 290 WppmVanadium 37 wppm nickel, 223 wt percent 'f i Theise mfuenals r pmferablyremoved from sulfur, and exhibited a gravity of 16.9 API and 21 Contheoil by dlssolvmg the oil therefrom w1th a hydrocarl radson Carbon numberof percent In each cxam bon solveom at a temperature w'thm the ra nge offrom ple, the extractant and the residua were continuously about to 100F and r a Pressure wrthm o range agitated by bubbling nitrogen throughthe tube. After of r about armospherro Pr o 500 psrg' The allowing theresidua and extractant to react for one partrcuraraolverrt ernployed notcrmcal but can be hour at atmospheric pressure, the tube was removed yeffectrye materral from P P o p to a refinery 20 from the bath and thecontents cooled. Thereafter, the naphtha Stream Preferred Solventsinclude paraffitllc treated 011 was contacted and stirred with 200millili hydrocarbons or mrXturoS thereof, wrth heptane bemg ters ofnormal heptane at room temperature for about Particularly Preferrodyp yr2 t0 P 1 hour. The total mixture was then centrifuged to rey 3 to 5,Volumes of Solvent are p y P Volume move the solids. The resultingsolids were thereafter of 25 washed with additional heptane to removeresidual oil Alternatively, separatlon can be acoompllshed y and thendried in air at room temperature. Both the re- P y P g the oil/SulfurmlXturo to Stand for a covered oil and the solid materials were analyzedusing period of time sufficient for the unreacted sulfur, the emissionspectroscopy techniques. The vanadium Group VB meta Salt, an the eac eda CO sesquesulfide (V 8 used in these examples was preplexed contaminantmetals, to settle out from the hypared by treating vanadium pentoxide (V0 with h drocarbon material. Substantially complete separation drogensulfide (H 5); about 50 percent of unreacted by settling will occurwithin about 8 hours. The settling vanadium pentoxide still remained inthe samples used. period can be markedly reduced by centrifuging theUnless otherwise stated, all parts and percentages are total mixture. byweight. Table 1 summarizes the results obtained.

TABLE I Example l Example 2 Example 3 Example 4 (control) (comparative)Extractant V 8 (1%) V 8 (1%) S (1%) (wt.% on feed) None S(l%) S(l0%)Temperature, C 25 200 X00 150 200 I00 200 I00 l 200 Treated Oil v, ppm140 110 125 30 110 26 100 79 Ni. m 20 12 5 5 5 22 3 13 10 10 s. wt.%2.23 1.9 2.7 3.1 1.8 10.2 6.7 3.1 6.0 2.0 Solids v. ppm 2050 2225 50005000 5000 2.3%) (1.4%) 2250 1800 2000 N1. pp 270 265 275 240 195 216 122260 190 235 5, WI.% 3.62 4.21 3.19 3.76 3.44 15.3 9.5 3.79 36.0 4.23Solids. wt.% on-fced 8.1 8.4 11.0 10.4 16.1 10.4 22.8 8.3 13.5 10.11

Example 5 Example 6 Example 7 (comparative) (comparative) (comparative)Extractant Na s (l%) Na s (5%) V20, l /r) V20, (5%) (wt.% onfced) s 10%s(1%) s(5% s(1%) s(5% Temperature, C 200 200 200 200 200 Treated on v.ppm 87 47 100 95 70 43 Ni. ppm 11 6 11 11 9 4 s, 911.96 7.4 6.3 1.1 1.91.7 2.0 Solids v. m 1625 1375 1825 1925 (0.99% 2.1%) Ni. m 190 238 213285 224 5. wt.% 25.6 15.9 2.86 5.02 4.57 6.87 sd1ids.wu1t on feed 10.515.8 9.0 10.0 12.7 27.0

TABLE I Continued Example 8 Example 9 (comparative) (comparative)Extractant V25; (2%) (wt.% on feed) S (2%) 7 Temperature, C 200 200Treated Oil V, ppm 63 88 Ni, ppm 7 l l 5, wt.% [.8 1.6 Solids V. ppm NotAvailable Not Available Ni, ppm Not Available Not Available S, wt.% NotAvailable Not Available Solids, wt.% on feed Not Determined NotDetermined J l5 Example 1 1s a control experiment and indicates the from0.1 to wt. percent based on the weight of the degree of metals removalwhich can be achieved achydrocarbon. cording to the processing schemeemployed without 6. A process according to claim 1 wherein the protheaddition of an extractant. Examples 2 and 3 illusmoter is dispersed on asupport material and the hydrotrate the highly efficient metals removalwhich can be carbon is contacted with the extractant by admixing theachieved by using the extractant according to the presy a n and e eemental Sulfur and passing the ent invention. As noted above, thevanadium sulfide l'fisllltaht miXtUfe Over the pported Group B metalused was, in fact, a mixture of V 8 and V 0 as added Salt at a Spacevelocity from 001 to 100 /h to the reaction zone. A comparison ofExamples 2 and P flccordlng t0 Glam 6 Wherem the Space 3 with Example 7shows, however, that a substantial veloclty 15 with! the "h of 1 t 5difference in performance is secured when one starts A Process aeeordmgto ela'm 1 Wherem the e with a mixture containing at least some vanadiumsultraetaht Separated from the hydrocarbon by allowmg fide as opposed tostarting with vanadium pentoxide. the extraetaht to semehom the.hydreearheh- Additionally, a comparison of the results of Examples Aphoeess aceordmg to Clam 1 wherem the e 2 and 3 to the results ofExamples 4 and 5 indicates a traePaht separated m the hydfoearbeh byclear Superiority of the use of the extractam of the pres solving theoil therefrom with a paraffmic hydrocarbon. ent invention as opposed tothe use of sulfur alone. 0 And, comparative Example 6 illustrates thatother ma- 1 A prochss accordlgg to 12} 1 wherelh e proterials such assodium sulfide do not function in the i f a "*3? 1 h h 7 same manner asthe vanadium material. accor. mg to i. am i h Comparison of Examples 2,8 and 9 shows a definite motegcompriges a mlxture 0 a Vana mm l esynergism in the use of mixtures of V 5 with sulfur i 2 t l 10 h thrather than the use of either component alone. .process.accor mg 0 c.almw .erem e pmmoter lS vanadium sesquesulfrde, vanadium pentasul- What isclaimed 18. 40

fide or a mixture thereof. 1. A process for reducing the level of metalcontaml- 13. A process for reducing the level of metal contamnants m ahydrocarbon material selected from the mants m a hydrocarbon materialselected from the group consisting of crude oil or a residual petroleumf d I I fraction which comprises contacting the hydrocarbon groupConsisting- 0 cm e a reel petro cum l t t b 400C fraction containing thesame which comprises contactmatena at a f g g i 3 w] b ing thehydrocarbon material at a temperature varying g h g g g s percenlt 1 3from 150 to 350C. with an extractantcomprising 0.05 t e to e f g 0 eemenia an to 5.0 wt. percent, based on the weight of the hydrocaraPromoter Se ecte mm 6 group. Conslstmg o bon, of elemental sulfur andfrom 0.1 to 10 wt. percent, ported and unsupported oxides, sulfides, andselemdes based on the weight of the hydrocarbon, of an unsuph of htantalum m'xthres thereof ported sulfide of vanadium and thereafterseparating at and themse where the Promoter unsupported the least aportion of the extractant and metal contamipromoter is present in anamount of from 0.] to 10 wt. ants f Said hydrocarbon Percent, based hthe Welght of e hydrocarbon, and 14. A process of claim 13 wherein saidextractant thereafter separating at leastaportron of the extractantcomprises from 0.9 to 15 wt percent, based on the h meta] cohtammamsfrom l hydrocarbon mate weight of the hydrocarbon, of elemental sulfurand 0.5 Hal. to 2.0 wt. percent of an unsupported sulfide of vana- 2. Aprocess according to claim 1 wherein the hydrodi carbon iS COl'ltfiCtfidwith the extractant at a tempera- 15, The process of claim 13 whereinthe extractant ture of from about 150 to 350C- is separated from thehydrocarbon material by dis- A Pmcess accol'dlng to Clalm 1 wherein theSulfur solving the hydrocarbon material with a paraffinic hyis presentin an amount of 0.5 to 5.0 wt. percent based drocarbon on the weight ofthe hydrocarbon. 16. The process of claim 14 wherein the extractant 4. Aprocess according to claim 3 wherein the sulfur is separated from thehydrocarbon material by disis present in an amount of from 0.9 to 1.5Wtp rcen solving the hydrocarbon material with a paraffinic hybased onthe weight of the hydrocarbon.

5. A process according to claim 1 wherein the prorngter isunsupportedand is present in an amount of drocarbon.

17. A process for reducing the level of metal contaminants in ahydrocarbon material selected from the group consisting of crude oil ora residual petroleum fraction which comprises contacting the hydrocarbonmaterial at a temperature below 400C. with an extractant comprising0.001 to 10 wt. percent, based on the weight of the hydrocarbon, ofelemental sulfur and an effective promoting amount of a promoterselected from the group consisting of the oxides, sulfides, andselenides of vanadium, tantalum, niobium or mixtures thereof, andthereafter separating at least a portion of the extractant and metalcontaminants from said hydrocarbon material, the promoter being presentin an based on the weight of the hydrocarbon.

V i =l

1. A PROCESS FOR REDUCING THE LEVEL OF METAL CONTAMINANTS IN AHYDROCARBON MATERIAL SELECTED FROM THE GROUP CONSISTING OF CRUDE OIL ORA RESIDUAL PETROLEUM FRACTION WHICH COMPRISES CONTACTING THE HYDROCARBONMATERIAL AT A TEMPERATURE BELOW 400*C. WITH AN EXTRACTANT COMPRISING0.001 TO 10WT. PERCENT, BASED ON THE WEIGHT OF THE HYDROCARBON, OFELEMENTAL SULFUR AND A PROMOTER SELECTED FROM THE GROUP CONSISTING OFSUPPORTED AND UNSUPPORTED OXIDES, SULFIDES, AND SELENIDES OF VANADIUM,TANTALUM, NIOBIUM OR MIXTURES THEREOF, AND IN THE CASE WHERE THE PROMOTEIS UNSUPPORTED THE PROMOTER IS PRESENT IN AN AMOUNT OF FROM 0.1 TO 10WT.PERCENT, BASED ON THE WEIGHT OF THE HYDROCARBON, AND THEREAFTERSEPARATING AT LEAST A PORTION OF THE ETRACTANT AND METAL CONTAMINANTSFROM SAID HYDROCARBON MATERIAL.
 2. A process accOrding to claim 1wherein the hydrocarbon is contacted with the extractant at atemperature of from about 150* to 350*C.
 3. A process according to claim1 wherein the sulfur is present in an amount of 0.5 to 5.0 wt. percentbased on the weight of the hydrocarbon.
 4. A process according to claim3 wherein the sulfur is present in an amount of from 0.9 to 1.5 wt.percent based on the weight of the hydrocarbon.
 5. A process accordingto claim 1 wherein the promoter is unsupported and is present in anamount of from 0.1 to 10 wt. percent based on the weight of thehydrocarbon.
 6. A process according to claim 1 wherein the promoter isdispersed on a support material and the hydrocarbon is contacted withthe extractant by admixing the hydrocarbon and the elemental sulfur andpassing the resultant mixture over the supported Group VB metal salt ata space velocity of from 0.01 to 100 v/v/hr.
 7. A process according toclaim 6 wherein the space velocity is within the range of 1 to 5 v/v/hr.8. A process according to claim 1 wherein the extractant is separatedfrom the hydrocarbon by allowing the extractant to settle from thehydrocarbon.
 9. A process according to claim 1 wherein the extractant isseparated from the hydrocarbon by dissolving the oil therefrom with aparaffinic hydrocarbon.
 10. A process according to claim 1 wherein thepromoter comprises a vanadium sulfide.
 11. A process according to claim10 wherein the promoter comprises a mixture of a vanadium sulfide andvanadium oxide.
 12. A process according to claim 10 wherein the promoteris vanadium sesquesulfide, vanadium pentasulfide or a mixture thereof.13. A process for reducing the level of metal contaminants in ahydrocarbon material selected from the group consisting of crude oil ora residual petroleum fraction containing the same which comprisescontacting the hydrocarbon material at a temperature varying from 150*to 350*C. with an extractant comprising 0.05 to 5.0 wt. percent, basedon the weight of the hydrocarbon, of elemental sulfur and from 0.1 to 10wt. percent, based on the weight of the hydrocarbon, of an unsupportedsulfide of vanadium and thereafter separating at least a portion of theextractant and metal contaminants from said hydrocarbon.
 14. A processof claim 13 wherein said extractant comprises from 0.9 to 1.5 wt.percent, based on the weight of the hydrocarbon, of elemental sulfur and0.5 to 2.0 wt. percent of an unsupported sulfide of vanadium.
 15. Theprocess of claim 13 wherein the extractant is separated from thehydrocarbon material by dissolving the hydrocarbon material with aparaffinic hydrocarbon.
 16. The process of claim 14 wherein theextractant is separated from the hydrocarbon material by dissolving thehydrocarbon material with a paraffinic hydrocarbon.
 17. A process forreducing the level of metal contaminants in a hydrocarbon materialselected from the group consisting of crude oil or a residual petroleumfraction which comprises contacting the hydrocarbon material at atemperature below 400*C. with an extractant comprising 0.001 to 10 wt.percent, based on the weight of the hydrocarbon, of elemental sulfur andan effective promoting amount of a promoter selected from the groupconsisting of the oxides, sulfides, and selenides of vanadium, tantalum,niobium or mixtures thereof, and thereafter separating at least aportion of the extractant and metal contaminants from said hydrocarbonmaterial, the promoter being present in an amount of from about 0.1 to10 wt. percent, based on the weight of the hydrocarbon.
 18. The processof claim 17 wherein the promoter is selected from the group consistingof vanadium sulfide, vanadium sesquesulfide, vanadium pentasulfide andmixtures thereof.
 19. The process of claim 18 wherein the temperatureranges frOm about 150* to 350*C.
 20. The process of claim 19 wherein thesulfur is present in an amount of from 0.5 to 5.0 wt. percent, based onthe weight of the hydrocarbon.